1. Field
Some example embodiments may generally relate to X-ray detectors having photoconductors including current resistance layers.
2. Description of Related Art
An X-ray detector that includes a thin film transistor may have drawn attention for use as a medical diagnosis device. An X-ray detector may output an X-ray image or an X-ray transparent image taken by using X-rays as a digital signal. X-ray detectors may be divided into direct-type X-ray detectors and indirect-type X-ray detectors.
In direct-type X-ray detectors, X-rays may be directly converted into charges by photoconductors, and in indirect-type X-ray detectors, after converting X-rays into visible light by using scintillators, the converted visible light may be converted into charges by using optical transducers, such as photodiodes.
Direct-type X-ray detectors may include photoconductors that generate electron-hole pairs by X-ray irradiation and pixel electrodes that receive charges from the photoconductor.
Materials used to form the photoconductor may include, for example, HgI2. Since HgI2 with a small thickness may easily absorb X-rays due to its large atomic number and ionization energy by X-rays may be very small, HgI2 may be used as a photoconductor material. However, HgI2 may have a high electrical conductivity and, thus, a current leakage that is generated during an X-ray measuring process may occur in the photoconductor. Also, since an amount of current that flows through the photoconductor may be large when a bias voltage is applied thereto before X-ray detection, the amount of current that is generated during X-ray detection may be relatively small and, thus, the X-ray detection efficiency may be low.